Accuracy: ?2″.
To inspect protractor, taper gage, index plate, index head and goniometer, can also be used to set angle.
Made of special alloy steel, hardness HRC64, high stability, wear resistance and easy combination.
Can be combined to any angle with interval 6 seconds after combination (6″, 12″, 18″, … , 360?).

3M 26018, PPS Series 2.0 Adapter, Type S11, 3/8 Male, 18 Thread NPS, 7100135942
Insize 6313-0D1, SETTING RING, .1" dia, 6928640357633
3M 82975, Roloc D/F Cool Running Disc Pad TR, 3 in 1/4-20 Internal, 7010309116
3M 26022, PPS Series 2.0 Adapter, Type S12, 10 mm Male, 1.0 mm Thread, 7100135943
3M 26046, PPS Series 2.0 Adapter, Type S15, 3/8 Male, 19 Thread BSP, 7100135334
3M 26138, PPS Series 2.0 Adapter, Type S42, 3/8 Female R-Angle, 19Thread BSP, 7100135930 